title: Carotid artery stiffness in patients with symptomatic carotid artery disease with contralateral asymptomatic carotid artery disease and in patients with bilateral asymptomatic carotid artery disease: a cine phase-contrast carotid MR study.
abstract: BACKGROUND
  Atherosclerosis is a systemic inflammatory disease that may affect multiple arterial beds simultaneously. Vascular distensibility is increasingly used in the clinical assessment of patients with atherosclerotic disease. In this study, we assess distensibility of symptomatic atherosclerotic carotid artery and of contralateral asymptomatic side. We also investigate the distensibility of bilaterally asymptomatic atherosclerotic carotid arteries using cine phase-contrast carotid magnetic resonance (MR) imaging.
  
  
  METHODS
  Nineteen patients with bilateral carotid artery disease underwent cine phase-contrast carotid imaging on a 1.5 T MR system. Ten patients had ipsilateral symptomatic carotid artery disease and contralateral asymptomatic stenosis. Nine additional patients with bilateral asymptomatic carotid artery disease constituted historical control group. Cine phase-contrast MR imaging acquired at the common carotid artery, maximum luminal stenosis, and internal carotid artery was used to determine carotid distensibility bilaterally for carotid arteries in both patient groups.
  
  
  RESULTS
  Symptomatic carotid arteries were found to be significantly less distensible (mean distensibility coefficient [DC] 35.4 ± 6.12 × 10(-3)/kPa) than the contralateral asymptomatic vessels (mean DC 54.4 ± 7.88 × 10(-3)/kPa, P = .03) at the level of the common carotid artery. A similar trend of high distensibility for asymptomatic side in the area of maximum stenosis and the internal carotid artery was seen, but it was not found to be statistically significant. Plaque burden was comparable between the 2 groups at all locations. DC was comparable for patients with bilateral asymptomatic carotid artery stenoses. Distensibility of bilaterally asymptomatic carotid arteries was greater than that of asymptomatic carotid artery contralateral to the symptomatic side.
  
  
  CONCLUSIONS
  Symptomatic carotid artery is stiffer than the contralateral asymptomatic side, despite comparable plaque burden. Patients with bilateral asymptomatic carotid artery disease have comparable stiffness. Larger studies are warranted to further investigate the findings of this MR study.
authors.affiliation: University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK; Department of Surgery, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK. Electronic address: sadat.umar@gmail.com.
authors.forename: Umar
authors.initials: U
authors.lastname: Sadat
authors.affiliation: Department of Cardiovascular Medicine, Cavalry Hospital, Lahore, Pakistan.
authors.forename: Ammara
authors.initials: A
authors.lastname: Usman
authors.affiliation: University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Simon P S
authors.initials: SP
authors.lastname: Howarth
authors.affiliation: University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Tjun Y
authors.initials: TY
authors.lastname: Tang
authors.affiliation: Department of Surgery, Great Western Hospital, Swindon, UK.
authors.forename: Fahreyar
authors.initials: F
authors.lastname: Alam
authors.affiliation: University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
authors.affiliation: University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Gillard
mesh_terms: D002339:Carotid Arteries / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000473:pathology*; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000473:pathology; D059289:Vascular Stiffness / Q000502:physiology*
keywords: Carotid artery; arterial stiffness; atheroma; atherosclerosis; distensibility; magnetic resonance imaging